RU2519240C2 - Fluid flow route control based on its characteristics for adjustment of underground well flow resistance - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention group refers to operation of an underground well and in particular to variants of system of control of fluid mix flow from geologic bed to a well or from a well to geologic bed. Such control for example provides for minimising water and/or gas recovery and maximising oil and/or gas recovery with balancing the recovery between zones. The essence of the invention by one of the variants: The system of variable flow resistance contains the first flowing channel and the first network from one or few take-out channels crossing the first flowing channel. At that, the invention provides for possibility of taking part of fluid mix from the first flowing channel to the first network of take-out channels and its variation, depending at least of viscosity of fluid mix or flow rate of fluid mix in flowing channel. The first network of take-out channels is capable of directing fluid mix to the first control channel of a flow path switch, which is able to select one of a range of flow paths, by which after switching the prevailing portion of fluid passes, at least partially depending on proportion of fluid mix taken out to the first control channel.

EFFECT: improving operating reliability of a system owing to its self-adjustment.

16 cl, 10 dwg

Description

BACKGROUND

The present invention relates, in General, to the equipment and operations performed during the operation of an underground well, and, in particular, to a variable flow resistance system.

A multiple advantage in a hydrocarbon well is the ability to control the flow of fluid mixtures from the geological formation to the well. Such regulation can serve various purposes, including preventing the formation of a water or gas cone in the formation, minimizing sand production, minimizing water and / or gas production, maximizing oil and / or gas production, balancing production between zones, and the like.

Typically, in an injection well, it is desirable to uniformly inject water, steam, gas, and the like. in many zones so that hydrocarbons are uniformly displaced along the geological formation, and so that the injected fluid mixture does not break prematurely to the production well. Thus, the ability to control the flow of a fluid mixture from a well into a geological formation can also be a useful feature for injection wells.

Therefore, it is not difficult to understand that in the above circumstances there is a need for improvements in the field of controlled restriction of fluid flow in the well, and such improvements could be useful in a wide variety of other circumstances.

SUMMARY OF THE INVENTION

The following is a description of a variable flow resistance system that makes improvements in the field of controlling fluid flow in a well. In particular, one embodiment has been described in which a fluid mixture is passed along a path with increased flow resistance if a value of some undesirable characteristic of this fluid has reached a threshold value or has exceeded a threshold value. In another embodiment described below, flow resistance as it passes through the system increases as the ratio of the desired fluid to the undesired fluid composition decreases.

In one aspect of the present invention, there is provided a variable flow resistance system for a fluid mixture in an underground well. This system may include a flow channel and a set of one or more bypass channels crossing the flow channel. In this way, a portion of the fluid mixture diverted from the flow channel to the outlet duct network varies depending on at least one of the following characteristics: a) the viscosity of the fluid mixture and b) the speed of the fluid mixture in the flow channel.

In another aspect of the present invention, a variable flow resistance system for an underground wellbore is described. This system may include a flow path switch that selects one of the many paths that the predominant portion of the fluid will go after exiting the switch, depending on the ratio of the desired fluid to the undesired fluid composition.

In yet another aspect, the variable flow resistance system of the fluid mixture may include a flow chamber. The predominant part of the fluid mixture enters the chamber in a direction that varies depending on the ratio of the content of the desired fluid to the undesirable in the composition of the fluid mixture.

In a further aspect, the present invention provides a variable flow resistance system for a fluid mixture in an underground well. This system includes a flow chamber, and the predominant part of the fluid mixture can enter the chamber in a direction that varies depending on the speed of the fluid mixture.

In yet another aspect, a variable flow resistance system for use in an underground well may include a flow chamber having an outlet and at least first and second inlets. The fluid mixture entering the flow chamber through the second inlet can counteract the flow of the fluid mixture entering the flow chamber through the first inlet, whereby the resistance to the flow of the fluid mixture through the flow chamber can vary depending on the ratio of flows through the first and second inlets.

These and other features and advantages of the present invention will be understood by qualified specialists after a careful consideration of the detailed description of the presented embodiments of the invention presented below with the accompanying drawings, in which similar elements in different figures are denoted by the same numbers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic partial cross-sectional view of a downhole system in which the principles of the present invention can be implemented.

FIG. 2 is an enlarged schematic cross-sectional view of a downhole filter and a variable flow resistance system that can be used in the downhole system of FIG. one.

FIG. 3 is a schematic “expanded” view of one configuration of a variable flow resistance system, taken along line 3-3 of FIG. 2.

FIG. 4 is a schematic top view of another configuration of a variable flow resistance system.

FIG. 5 is an enlarged schematic top view of part of a variable flow resistance system of FIG. four.

FIG. 6 is a schematic plan view of yet another configuration of a variable flow resistance system.

FIG. 7A and 7B are a schematic plan view of the next configuration of a variable flow resistance system.

FIG. 8A and 8B are a schematic plan view of yet another configuration of a variable flow resistance system.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1 shows an embodiment of a downhole system 10 in which the principles of the present invention can be implemented. As shown in FIG. 1, well 12 has a generally vertical uncased section 14 extending downward from the casing 16, as well as a generally horizontal uncased section 18 extending through the geological formation 20.

A pipe string 22 is installed in the well 12 (for example, a production pipe string). A plurality of interconnected downhole filters 24, variable flow resistance systems 25, and gaskets 26 are installed in the tubing string 22.

Sealers 26 isolate the annulus 28 formed in the radial direction between the pipe string 22 and the well section 18. In this way, fluids 30 can be produced from multiple horizons or zones of the formation 20 through isolated portions of the annulus 28 formed between adjacent pairs of seals 26.

Between each pair of adjacent seals 26 in the pipe string 22 are interconnected downhole filter 24 and a variable flow resistance system 25. The downhole filter 24 filters the fluids 30 entering the pipe string 22 from the annulus 28. The variable flow resistance system 25 controls the passage of fluids 30 into the pipe string 22, restricting flow in different ways depending on the specific characteristics of these fluids.

It should be noted here that the downhole system 10 is described and shown in the drawings merely as one example from a wide variety of downhole production systems in which the principles of the present invention can be implemented. It should be clearly understood that the principles of the present invention are not at all limited to any details of the borehole system 10 or its components shown in the drawings or in the description.

For example, in accordance with the principles of the present invention, it is not necessary for the well 12 to contain a generally vertical section 14 or a generally horizontal section 18. It is not necessary that the fluids 30 are only extracted from the formation 20, since in other examples, the fluids may be injected into the reservoir, and fluids can be either injected into the reservoir, or extracted from the reservoir, etc.

It is not necessary that between each adjacent pair of seals 26 there should be a downhole filter 24 and a variable flow resistance system 25. It is not necessary that one variable flow resistance system 25 be used in conjunction with one downhole filter 24. These components may be used in any quantity, in any order and / or combination.

It is not necessary that any variable flow resistance system 25 be used with the downhole filter 24. For example, in injection operations, the pumped fluid may pass through the variable flow resistance system 25 without passing through the downhole filter 24.

It is not necessary that the downhole filters 24, variable flow resistance systems 25, seals 26, and any other components of the tubing string 22 are located in uncased portions 14, 18 of the well 12. In accordance with the principles of the present invention, any portion of the well 12 can be cased or not cased , and any part of the tubing string 22 may be located in an uncased or cased portion of the well.

Thus, it should be clearly understood that the present description illustrates how certain embodiments of the present invention can be implemented and applied, but the principles of the invention are not limited to any details of such options. On the contrary, these principles can be applied to many other options based on knowledge obtained from this description.

Qualified specialists in this field will understand that it would be very beneficial to be able to control the flow of fluids 30 into the pipe string 22 from each zone of the formation 20, for example, to prevent the formation of a water cone 32 or a gas cone 34 in the formation. Other goals of applying flow control in a well include, but are not limited to, balancing production from or from multiple zones, minimizing production or injection of unwanted fluids, maximizing production or injection of desired fluids, etc.

The embodiments of the variable flow resistance systems 25, described in detail below, can provide these benefits by increasing the flow resistance when the fluid velocity rises above a selected level (for example, to thus balance flow between zones, to prevent the formation of water or gas cone, etc.), by increasing the resistance to flow in the case when the viscosity or density of the fluid decreases to a value below the selected level (for example, to thus restricting the flow of undesirable fluid, say water or gas, in an oil well), and / or by increasing the flow resistance when the viscosity or density of the fluid increases to a value higher than the selected level (for example, in such a way as to minimize water injection in the process of injecting steam into the well).

Which fluid is desired and which is undesirable depends on the purpose of the production or injection operations performed. For example, if you want to extract oil from a well, but not to produce water or gas, then oil is a desirable fluid, and water and gas are undesirable fluids. If it is required to produce gas from a well, but not to produce water or oil, then the desired fluid is gas, and the undesirable fluids are water and oil. If it is desired to inject steam into the formation but not to inject water, then steam is a desirable fluid and water is an undesirable fluid.

It should be noted that, at temperatures and pressures that are available at great depths, a hydrocarbon gas can actually partially or completely remain in the liquid phase. Therefore, it should be understood that when using the term "gas" in this description, it includes the supercritical, liquid or gas phase of this fluid.

In FIG. 2 is an enlarged sectional view of one embodiment of a variable flow resistance system 25 and part of one downhole filter 24. In this embodiment, a fluid mixture 36 (which may include one or more fluids, such as oil and water, liquid water and steam, oil and gas , gas and water, oil, water and gas, etc.) passes into the downhole filter 24, is filtered there and then passes into the entrance 38 of the variable flow resistance system 25.

The fluid mixture may contain one or more desirable or undesirable fluids. The composition of the fluid mixture may combine water and steam. In another example of a fluid mixture, oil, water and / or gas may be combined.

The flow of the fluid mixture 36 through the variable flow resistance system 25 experiences a resistance depending on one or more characteristics (e.g., density, viscosity, speed, etc.) of the fluid mixture. Then the fluid mixture 36 leaves the system 25 of variable resistance to flow and passes into the pipe string 22 through the outlet 40.

In other embodiments, the downhole filter 24 may not be used in combination with the variable flow resistance system 25 (for example, in injection operations), and the fluid mixture 36 may pass in the opposite direction through various elements of the downhole system 10 (for example, in injection operations), while one variable flow resistance system can be used in combination with many downhole filters, many variable flow resistance systems can be used in combination with one or more downhole filters and filters, and the fluid mixture can come from the well sections (or exit into those sections) that are not related to the annulus or pipe string, the fluid mixture can pass through a variable flow resistance system before passing through the well filter, any other components can be interconnected upstream or downstream of the downhole filter and / or variable flow resistance system and the like. Thus, it should be understood that the principles of the present invention are not at all limited to the details of the embodiment shown in FIG. 2 and described here.

Although shown in FIG. 2, a well filter 24 refers to a type of wire-wound well filter known in the art; in other embodiments, any other type or combination of well filter may be used (for example, sintered powder filters, volumetric, mesh, sprayed, and the like). In addition, optional components can be used (for example, casings, bypass pipes, pipelines, instrumentation, sensors, flow regulators, etc.).

In FIG. Figure 2 shows a variable flow resistance system 25 in a simplified form, but in a preferred embodiment, this system may include various channels and devices for performing various functions, as described in detail below. In addition, in a preferred embodiment, the system 25 is at least partially located, protruding around the circumference around the pipe string 22, or this system can be formed in the wall of the pipe structure associated with the pipe string as part of it.

In other examples, the system 25 may not be located around the pipe string or may not be formed in the wall of the pipe structure. For example, system 25 may be formed in a flat structure, etc. The system 25 can be located in a separate housing attached to the pipe string 22, or it can be oriented so that the axis of the outlet 40 is parallel to the axis of the pipe string. The system 25 may be in the control circuit or connected to a device whose shape is different from the pipe. In accordance with the principles of the present invention, any orientation or configuration of the system 25 can be applied.

In FIG. 3 is a more detailed sectional view of one embodiment of system 25. FIG. 3, the system 25 is shown as if it was “deployed” from its ring-shaped configuration to a flat configuration.

As described above, the fluid mixture 36 enters the system 25 through the inlet 38, and exits the system through the outlet 40. The resistance to the flow of the fluid mixture 36 as it passes through the system 25 varies depending on one or more characteristics of this fluid mixture. Presented in FIG. 3, system 25 is in many ways similar to the system of FIG. 23 of the previous application with serial number 12/700685 included here by the above link.

In the embodiment of FIG. 3, the fluid mixture 36 initially enters a plurality of flow channels 42, 44, 46, 48. These flow channels 42, 44, 46, 48 direct the fluid mixture 36 to two flow path switches 50, 52. The switch 50 selects which of the two paths 54, 56, the predominant part of the flow of fluid mixture from the flow channels 44, 46, 48 will arrive, and the other switch 52 selects which of the two paths 58, 60 will receive the predominant part of the flow of fluid mixture from the flow channels 42, 44, 46, 48.

The flow channel 44 is configured to more restrict the flow of fluids having high viscosity. With increasing viscosity of the fluids in the flow, the flow channel 44 will increase the restriction of this flow.

The term “viscosity” as used herein is used to mean both Newtonian and non-Newtonian rheological properties, including kinematic viscosity, yield strength, viscoplasticity, surface tension, wetting ability, and the like. For example, the desired fluid may have kinematic viscosity, wettability, yield strength, viscoplasticity, surface tension, wettability, and the like within a desired range.

The flow channel 44 may have a relatively small flow area, this flow channel may cause the flow to move inside the channel along a curved path; it is possible to increase the resistance to flow of a fluid with increased viscosity by applying a rough surface or by installing obstructive structures on the flow path, etc. However, a relatively low viscosity fluid stream may pass through the flow channel 44 while experiencing relatively low resistance.

The control channel 64 of the flow switch 50 receives a fluid passing through the flow channel 44. The control hole 66 at the end of the control channel 64 has a reduced flow area, thereby increasing the speed of the fluid exiting the control channel.

The flow channel 48 is configured so that its flow resistance is relatively insensitive to the viscosity of the fluids passing through it, but could increase in the case of a fluid flow with increased speed and / or density. The flow of fluids with increasing viscosity when passing through the flow channel 48 may experience increasing resistance, but not increasing to such a degree as the resistance experienced by such fluids when passing through the flow channel 44.

In the embodiment of FIG. 3, the fluid passing through the flow channel 48 must pass through the “swirl” chamber 62 before it enters the control channel 68 of the flow path switch 50. Since the chamber 62 in this embodiment has a cylindrical shape with a central outlet, and the fluid mixture 36 moves in the chamber in a spiral, increasing speed as it approaches the exit under the influence of the pressure drop between the inlet and the outlet, such a camera is called a "vortex" camera. In other embodiments, one or more openings, venturi tubes, nozzles, and the like can be used.

The control channel 68 ends with a control hole 70. This control hole 70 has a reduced flow area in order to increase the speed of the fluid exiting the control channel 68.

It is easy to understand that with an increase in the viscosity of the fluid mixture 36, most of the fluid mixture will flow through the flow channel 48, the control channel 68 and the control hole 70 (due to the fact that the flow channel 44 exerts higher viscosity flow to the fluid than the flow channel 48 and vortex camera 62). Conversely, with a decrease in the viscosity of the fluid mixture 36, most of it will flow through the flow channel 44, the control channel 64 and the control hole 66.

The fluid passing through the flow channel 46 also passes through the vortex chamber 72, which may be similar to the vortex chamber 62 (although the vortex chamber 72 preferably has less resistance to the flow passing through it than the vortex chamber 62) and exits into the central flow chamber channel 74. The vortex chamber 72 is used to "match the impedances" in order to achieve the desired balance of flows through the flow channels 44, 46, 48.

It should be noted that the dimensions and other characteristics of the various components of the system 25 must be selected accordingly to achieve the desired results. In the embodiment of FIG. 3, one desired result of the operation of the flow path switch 50 is that the flow of the main part of the fluid mixture 36 passing through the flow paths 44, 46, 48 is directed to the flow path 54 when the fluid mixture has a sufficiently high ratio of the desired fluid content environment to undesirable in its composition.

In this example, the desired fluid is oil having a higher viscosity than water or gas, and thus, if the fluid mixture 36 contains a sufficiently high percentage of oil, the bulk of the fluid 36 entering the flow path switch 50 will be directed to path 54 of the stream, not path 56 of the stream. This result is achieved due to the fact that the flow rate or velocity of the fluid exiting the control hole 70 will be greater than that of the fluid exiting the other control hole 66, as a result of which the fluid exiting the channels 64, 68, 74 is forced to pass more to the flow path 54.

If the viscosity of the fluid mixture 36 is not high enough (and therefore the ratio of the desired fluid to the undesirable is below the selected level), then the bulk of the fluid mixture (or at least most of it) entering the flow path switch 50 will be directed to path 56 of the stream, and not to path 54 of the stream. This is due to the fact that the flow rate, speed and / or kinetic energy of the fluid exiting the control hole 66 will be greater than that of the fluid exiting the other control hole 70, as a result of which the fluid exiting the channels 64, 68, 74, forced to go more to the path of flow 56.

It is easy to understand that using the corresponding configuration of the flow channels 44, 46, 48, control channels 64, 68, control holes 66, 70, vortex chambers 62, 72, etc. the ratio of the desired fluid content to the undesired fluid in the fluid mixture 36, in which the switch 50 directs the bulk of the fluid flow through it, either to flow path 54 or to flow path 56, can be set to different levels.

The flow paths 54, 56 direct the fluid to the respective control channels 76, 78 of the other flow path switch 52. The control channels 76, 78 end with the corresponding control holes 80, 82. The central channel 75 receives fluid from the flow channel 42.

The operation of the flow path switch 52 is similar to the operation of the flow path switch 50 in that the fluid entering the switch 52 through channels 75, 76, 78 is mainly directed to one of the flow paths 58, 60, and the choice of flow path depends on the speed ratio fluid exiting control ports 80, 82. If fluid passes through control port 80 at a flow rate, speed and / or kinetic energy greater than that of fluid passing through control port 82, then the predominant part (or at least , most) of the fluid mixture 36 will be directed to the flow path 60. If the fluid passes through the control hole 82 with a flow, speed and / or kinetic energy greater than that of the fluid passing through the control hole 80, then the predominant part (or, at least a large part) of the fluid mixture 36 will be directed to the flow path 58.

Although in the embodiment of system 25 of FIG. 3, two flow path switches 50, 52 are shown, but it is easy to understand that any number of flow path switches (including one) can be used in accordance with the principles of the present invention. Presented in FIG. 3, switches 50, 52 relate to types of devices that are known to those skilled in the art as fluid-to-liquid ratio enhancers, however, in accordance with the principles of the present invention, flow path switches related to other types of devices (e.g., fluid-to-fluid amplifiers can be used) based on pressure, bistable fluid switches, proportional fluid ratio amplifiers, etc.).

The fluid flowing along flow path 58 enters the flow chamber 84 through an inlet 86, which directs the fluid entering the chamber generally tangentially (for example, the chamber 84 has a shape similar to a cylinder and the inlet 86 is tangential to the circumference of the cylinder). As a result, the fluid will spiral in chamber 84 until it eventually exits through outlet 40, as shown schematically by arrow 90 in FIG. 3.

The fluid passing through the flow path 60 enters the flow chamber 84 through an inlet 88, which directs this fluid along a more direct path to the outlet 40 (for example, in the radial direction, as shown schematically by arrow 92 in Fig. 3). It is easy to understand that the energy consumption at the same flow rate will be much less if the fluid passes to the outlet 40 in a more rectilinear manner than when the fluid moves to the outlet in a less rectilinear manner.

Thus, the flow will experience less resistance when the fluid mixture 36 goes to the outlet 40 in a more direct way, and vice versa, the flow will experience more resistance when the fluid mixture passes to the exit in a less direct way. Accordingly, in the section upstream of the outlet 40, the flow experiences less resistance when the bulk of the fluid mixture 36 passes into the chamber 84 through the inlet 88 and along the flow path 60.

The predominant part of the fluid mixture 36 passes along the flow path 60 in the case when the flow rate, speed and / or kinetic energy of the fluid flow exiting the control hole 80 is greater than that of the fluid exiting the control hole 82. More fluid exits the control hole 80 in the case when the main part of the fluid passing through the channels 64, 68, 74, passes along the flow path 54.

The predominant part of the fluid passing through the channels 64, 68, 74 passes along the flow path 54 in the case when the flow rate, speed and / or kinetic energy of the fluid exiting the control hole 70 is greater than that of the fluid exiting the control hole 66. A larger amount of fluid exits the control hole 70 when the viscosity of the fluid mixture 36 exceeds a selected level.

Thus, the flow through the system 25 will experience less resistance if the fluid mixture 36 has a higher viscosity (and a higher ratio of the content of the desired fluid to undesirable in its composition). The flow through system 25 will experience greater resistance when the fluid mixture 36 has a reduced viscosity.

Greater flow resistance will be provided when the fluid mixture 36 passes to the outlet 40 less straightforward (for example, as shown by arrow 90). Consequently, the flow will experience greater resistance when the bulk of the fluid mixture 36 enters the chamber 84 from the inlet 86 and along the flow path 58.

The predominant part of the fluid mixture 36 passes along the flow path 58 in the case where the flow rate, speed and / or kinetic energy of the fluid stream exiting the control hole 82 is greater than that of the fluid exiting the control hole 80. More fluid exits the control hole 82 in the case when the main part of the fluid passing through the channels 64, 68, 74, passes along the path 56 of the stream, and not along the path 54 of the stream.

The predominant part of the fluid passing through the channels 64, 68, 74, passes along the path of the stream 56 in the case when the flow rate, speed and / or kinetic energy of the fluid exiting the control hole 66 is greater than that of the fluid exiting the control hole 70. A larger amount of fluid exits the control hole 66 when the viscosity of the fluid mixture 36 is below a selected level.

As described above, system 25 is configured to provide less resistance to the flow when the fluid mixture 36 has an increased viscosity and to provide greater resistance to the flow when the fluid mixture has a reduced viscosity. This is advantageous when more high viscosity fluid and less low viscosity fluid are required to be passed (for example, to produce more oil and less water or gas).

If more fluid of lower viscosity and less fluid of higher viscosity are to be passed (for example, to produce more gas and less water or to pump more steam and less water), then the configuration of system 25 can be easily reconfigured for this goals. For example, the inlets 86, 88 can be easily interchanged, as a result of which the fluid passing along the flow path 58 will be directed to the inlet 88, and the fluid passing along the flow path 60 will be directed to the inlet 86.

In FIG. 4 shows another configuration of the variable flow resistance system 25, which in some respects is similar to the configuration of FIG. 3, but also somewhat different, in particular, in that in the system of FIG. 4 vortex chambers 62, 72 are not used for flow channels 46, 48, and a separate flow channel 42 is not used connecting the input 38 with the flow path switch 52. Instead, the flow channel 48 connects the input 38 to the central channel 75 of the switch 52.

A number of spaced-apart exhaust channels 94a-c intersect the flow channel 48 and provide a fluid connection between this flow channel and the control channel 68. Corresponding chambers 96a-c are formed at the intersection points of the exhaust channels 94a-c with the flow channel 48.

An increasing portion of the fluid mixture 36 passing through the flow channel 48 will pass into the outlet channels 94a-c as the viscosity of the fluid mixture increases or as the speed of the fluid mixture decreases. Therefore, the fluid will pass through the control hole 70 of the switch 50 with a high flow rate, speed and / or kinetic energy (compared to the flow rate, speed and / or kinetic energy of the fluid passing through the control hole 66) as the viscosity of the fluid increases or reducing the speed of the fluid mixture in the flow channel 48.

Preferably, the system 25 of FIG. 4 was configured so that the relationship between the ratio of flows through control openings 66, 70 and a portion of the desired fluid in the fluid mixture 36 was represented by a linear or monotonic function. For example, if the desired fluid is oil, then the ratio of the flow through the control hole 70 to the flow through the control hole 66 may vary depending on the portion of the oil in the fluid mixture 36.

The presence of chambers 96a-c is not strictly necessary, but allows you to increase the effect of viscosity on the fluid outlet to the outlet channels 94a-c, can be considered “whirlpool” chambers, since they form a volume in which the fluid mixture 36 can act on itself, thereby increasing fluid outlet as its viscosity increases. For the formation of chambers 96a-c, various shapes, volumes, surface treatment methods, surface topography and the like can be used to increase the effect of viscosity on the fluid outlet to the outlet channels 94a-c.

Although in FIG. 4, three tap channels 94a-c are shown, however, any number (including one) of tap channels can be used in accordance with the principles of the present invention. The outlet channels 94a-c are spaced apart from each other in the same line on one side of the flow channel 48, as shown in FIG. 4, but in other embodiments, in accordance with the principles of the present invention, they can be arranged radially, in a spiral or otherwise with respect to each other at certain intervals between them, and in addition, they can be located on either side (s) of the flow channel 48.

As can be seen more clearly in FIG. 5, the flow channel 48 preferably increases the width (and hence the flow section) at each intersection of the branch ducts 94a-c with the flow channel. Therefore, the width w2 of the flow channel 48 exceeds the width w1 of the flow channel, the width w3 exceeds the width w2, and the width w4 exceeds the width w3. Each increase in width is preferably located on the side of the flow channel 48, which crosses the corresponding outlet channel from the channels 94a-c.

The width of the flow channel 48 increases at each intersection with the outlet channels 94a-c in order to compensate for the expansion of the flow of the fluid mixture 36 through the flow channel. Preferably, a stream of jet-like fluid mixture 36 is maintained as each of the intersection points passes. In this way, fluids with a higher speed and lower viscosity will be less susceptible to being diverted to the outlet channels 94a-c.

The intervals between the intersections of the outlet channels 94a-c with the flow channel 48 may be the same (as shown in Figs. 4 and 5) or unequal. The distances between the outlet channels 94a-c are desirably selected so as to maintain an inkjet type flow of the fluid mixture 36 through the flow channel 48 at each intersection, as mentioned above.

In the system of FIG. 4 and 5, the desired fluid has a higher viscosity than the undesired fluid, and therefore the configurations of various elements of the system 25 (for example, flow channels 44, 48, control channels 64, 68, control openings 66, 70, outlet channels 94a-c, chambers 96a-c and the like), respectively, are selected such that the switch 50 directs the predominant part (or at least a large part) of the fluid passing through the channels 44, 46, 48, to the flow path 54 in the case when the fluid mixture has a sufficiently high viscosity. If the viscosity of the fluid mixture 36 is not high enough, the switch 50 directs the predominant part (or at least a large part) of the fluid to the flow path 56.

If the predominant portion of the fluid is directed to the flow path 54 (ie, if the fluid mixture 36 has a sufficiently high viscosity), then the switch 52 will direct the bulk of the fluid mixture to the flow path 60. Therefore, a significantly larger portion of the fluid mixture 36 will pass into the chamber 84 through the inlet 88 and follow to the outlet 40 along a relatively straight path with less resistance.

If the bulk of the fluid is directed by the switch 50 to the flow path 56 (ie, if the fluid mixture 36 has a relatively low viscosity), then the switch 52 will direct the bulk of the fluid to the flow path 58. Therefore, a significantly larger portion of the fluid mixture 36 will pass into the chamber 84 through the inlet 86 and follow to the exit 40 along a relatively curved path with high resistance.

Therefore, it is not difficult to understand that the system 25 of FIG. 4 and 5 increase the flow resistance of fluid compositions having a relatively low viscosity and reduce the flow resistance of fluid compositions with a relatively high viscosity. The viscosity level at which the resistance to flow through the system 25 can grow up from certain levels or fall down from them can be determined by choosing the appropriate configurations of the various elements of the system.

Similarly, if the fluid passing through the flow channel 48 has a relatively low speed, then a proportionally larger amount of this fluid will be diverted from the flow channel to the discharge channels 94a-c, which will increase the ratio of the fluid flow through the control hole 70 to the flow fluid through the control hole 66. As a result, the predominant part (or at least a large part) of the fluid mixture will pass through the inlet 88 into the chamber 84, and this fluid mixture will go along a relatively pit the way to exit 40, experiencing less resistance.

Conversely, if the fluid passing through the flow channel 48 has a relatively high speed, then a proportionally smaller amount of this fluid will be diverted from the flow channel to the discharge channels 94a-c, which will lead to a decrease in the ratio of the fluid flow through the control hole 70 to the fluid flow through the control hole 66. As a result, the predominant part (or at least a large part) of the fluid mixture 36 will pass through the inlet 86 into the chamber 84, and this fluid mixture will flow along a relatively curved path to exit 40, experiencing greater resistance.

Therefore, it is not difficult to understand that the system 25 of FIG. 4 and 5 increases the resistance to flows of fluid compositions having a relatively high speed, and decreases resistance to flows of fluid compositions having a relatively low speed. The level of speed at which the flow resistance from the side of the system 25 grows up from a certain level or falls down from it, can be determined by choosing the appropriate configuration of the various elements of the system.

In one preferred embodiment of system 25, a fluid stream having a relatively low viscosity (e.g., high gas fluid mixture 36) is resisted by the system regardless of its speed (above the minimum threshold speed). However, a fluid stream having a relatively high viscosity (for example, a high oil content fluid mixture 36) experiences resistance from the system only when its speed exceeds a selected level. Again, these characteristics of the system 25 can be determined by setting the appropriate configuration of the various elements of the system.

In FIG. 6 shows another configuration of the system 25. The configuration of FIG. 6 is much like the configuration of FIG. 4 and 5, but differs in that the fluid from both flow channels 44, 48 passes into the central channel 75 of the device 52, and a series of branch pipes 98a-c separated from each other crosses the flow channel 44, forming at the intersection points of the chamber 100a-c . In accordance with the principles of the present invention, you can select any number of branch channels 98a-c and chambers 100a-c (including one), their sizes, configuration and intervals between them.

Similar to the outlet channels 94a-c and chambers 96a-c described above, the outlet channels 98a-c and the chambers 100a-c perform the function of diverting a proportionally larger amount of fluid from the flow channel 44 (and to the central channel 75 of the device 52) as the viscosity of the fluid increases 36 or as the speed of the fluid mixture in the flow channel decreases. Therefore, the amount of fluid entering the control hole 66 will be proportionally reduced with an increase in the viscosity of the fluid mixture 36 or with a decrease in the speed of the fluid mixture in the flow channel 44.

As more fluid enters the control port 70 as the viscosity of the fluid mixture 36 increases or as the speed of the fluid in the flow channel 48 decreases (as described above for the configuration of FIGS. 4 and 5), the ratio of the amount of fluid passing through the control hole 70, to the amount of fluid passing through the control hole 66, when the viscosity of the fluid mixture 36 increases or the speed of the fluid mixture decreases, it increases significantly more in the configuration of FIG. 6 than in the configuration of FIG. 4 and 5.

Conversely, the ratio of the amount of fluid passing through the control hole 70 to the amount of fluid passing through the control hole 66, when the viscosity of the fluid mixture 36 decreases or as the speed of this fluid increases, decreases significantly more in the configuration of FIG. 6 than in the configuration of FIG. 4 and 5. Therefore, the system 25 of FIG. 6 is significantly more sensitive to changes in viscosity or velocity of the fluid mixture 36 than the system of FIG. 4 and 5.

Another difference of the system of FIG. 6 is that the chambers 96a-c and the chambers 100a-c gradually decrease in volume in the direction of flow along the respective flow channels 48, 44. Therefore, the volume of the chamber 96b is less than the volume of the chamber 96a, and the volume of the chamber 96c is less than the volume 96b cameras. Similarly, the volume of the chamber 100b is less than the volume of the chamber 100a, and the volume of the chamber 100c is less than the volume of the chamber 100b.

These changes in the volume of the chambers 96a-c and 100a-c can help to compensate for changes in the flow rate, flow rate and other parameters of the fluid mixture 36 through the corresponding channels 48, 44. For example, at each subsequent intersection of the discharge channels 94a-c with the flow channel 48 fluid through the flow channel 48 will fall, and the volume of the corresponding chamber of the plurality 96a-c will accordingly decrease. Similarly, at each subsequent intersection of the discharge channels 98a-c with the flow channel 44, the flow rate of the fluid through the flow channel 44 will decrease, and the volume of the corresponding chamber from the plurality of 100a-c will decrease accordingly.

One advantage of the systems of FIG. 4-6 compared with the system of FIG. 3 consists in the fact that all flow channels, flow paths, control channels, tap channels and other elements in the configurations of FIG. 4-6 are preferably located in the same plane (as seen in the drawings). It is obvious that when the system 25 is located around the circumference outside or inside the pipe structure, it is desirable that the channels, flow paths, etc. located at the same radial distance inside or outside such a pipe structure. This makes the manufacture of system 25 less complicated and expensive.

In FIG. 7A and B show another configuration of a variable flow resistance system 25. System 25 of FIG. 7A and B are much simpler than the systems of FIG. 3-5, at least in part because it does not contain flow path switches 50, 52.

Flow chamber 84 of FIG. 7A and B are also somewhat different in that the flow of the fluid mixture 36 to the two inlets 116, 110 of the chamber is supplied through two flow paths 110, 112 that direct the flow of the fluid mixture in opposite directions with respect to the outlet 40. As shown in FIG. 7A and B, the fluid entering the chamber 84 through the inlet 116 is guided clockwise around the outlet 40, and the fluid entering the chamber through the inlet 110 is directed counterclockwise around the outlet.

In FIG. 7A, system 25 is shown in a situation where due to the increased speed and / or reduced viscosity of the fluid mixture 36, the predominant portion of the fluid mixture passes into the chamber 84 through the inlet 116. As a result, the fluid mixture 36 spirals around the outlet 40 in the chamber 84, and the resistance of the system 25 the flow rises. The reduced viscosity may be the result of a relatively low ratio of the desired fluid to the undesired fluid composition 36.

A relatively small amount of fluid mixture 36 passes into chamber 84 through inlet 110 in FIG. 7A, since the flow channel 114 is connected to branch channels 102a-c branching from the flow channel 112 at the swirl chambers 104a-c. At relatively high speeds and / or low viscosities, the fluid mixture 36 tends to pass past the vortex chambers 104a-c, as a result, a significant amount of the fluid mixture will not pass through the vortex chambers and outlet ducts 102a-c to the flow passage 114.

In FIG. 7B, the speed of the fluid mixture decreased and / or the viscosity of the fluid mixture increased, resulting in a proportional increase in the amount of fluid flowing through channel 112 to the exhaust channels 102a-c and through channel 114 to inlet 110. Since the flows into the chamber 84 are from two inlets 116 and 110 directed opposite, they oppose each other, as a result of destroying the vortex 90 in the chamber.

As shown in FIG. 7B, the fluid mixture 36 moves to a lesser degree in a spiral around the outlet 40 and to a greater extent rectilinearly to the outlet, thereby reducing the flow resistance from the system 25 side. Therefore, the flow resistance from the system 25 side decreases with decreasing speed of the fluid mixture 36, with increasing the viscosity of the fluid mixture or by increasing the ratio of the content of the desired fluid to the undesirable in the composition of the fluid mixture.

In FIG. 8A and B show yet another configuration of a variable flow resistance 25 system. System 25 of FIG. 8A and B are in many ways similar to the system of FIG. 7A and B, but differs at least in that in the configuration of FIG. 8A and B, it is not necessary to use branch channels 102a-c and swirl chambers 104a-c. Instead, the flow channel 114 itself branches off from the flow channel 112.

Another difference is that in the chamber 84 of the configuration of FIG. 8A and B, designs 106 are used to facilitate circular flow. The function of these structures 106 is to maintain the circular motion of the flow of the fluid mixture 36 at the outlet 40, or at least to prevent the flow of the fluid mixture inward to the exit when the flow of the fluid mixture moves in a circle at the exit. Holes 108 in structures 106 allow fluid mixture 36 to eventually pass inward to exit 40.

Structures 106 are an example of how the configuration of system 25 can be changed to obtain the desired flow resistance (for example, when the fluid mixture 36 has a given viscosity, speed, density, ratio of the desired fluid to the undesired fluid composition, etc.) . The method by which the flow channel 114 branches off from the flow channel 112 is another example of how the configuration of the system 25 can be changed to obtain the desired flow resistance value.

In FIG. 8A, system 25 is shown in a situation where, due to the increased speed and / or reduced viscosity of the fluid mixture 36, the bulk of the fluid mixture passes into the chamber 84 through the inlet 116. As a result, the fluid mixture 36 spirals around the outlet 40 in the chamber 84, and the resistance of the system 25 the flow rises. The reduced viscosity may result from a relatively low ratio of the desired fluid to the undesired fluid 36.

A relatively small amount of fluid mixture 36 passes into chamber 84 through inlet 110 in FIG. 8A, since the flow channel 114 branches off from the flow channel 112 so that the predominant portion of the fluid mixture remains in the flow channel 112. At relatively high speeds and / or low viscosities, the fluid mixture 36 tends to pass past the flow channel 114.

In FIG. 8B, the speed of the fluid mixture 36 decreased and / or the viscosity of the fluid mixture increased, resulting in a proportional increase in the amount of fluid flowing from the channel 112 through the channel 114 to the inlet 110. The increased viscosity of the fluid mixture 36 may be the result of an increased ratio of the desired fluid content to the undesired composition of the fluid mixture.

Since the flows into the chamber 84 from the two inlets 116 and 110 are directed oppositely (or at least the flow of the fluid mixture through the inlet 110 is opposite to the flow through the inlet 116), they oppose each other, thereby destroying the vortex 90 in the chamber. Therefore, the fluid mixture 36 passes in a more direct way to the outlet 40, and the flow resistance from the side of the system 25 is reduced.

It should be noted that any of the above features of any of the configurations of the system 25 can be included in any of the other configurations of the system, and therefore it should be understood that these features are not exclusive to any one specific configuration of the system. System 25 can be used in any type of borehole production system (for example, not only in borehole production system 10), as well as for performing various tasks in the well’s operation, including (but not limited to) injection, stimulation of the flow, opening of the formation, production, coverage of the area drilling operations, etc.

It can now be appreciated that the invention described above provides a number of improvements in the field of controlling fluid flow in an underground well. The system can provide different resistance to the flow of the fluid depending on various characteristics (for example, viscosity, density, speed, etc.) of the fluid mixture passing through the variable flow resistance system.

In particular, the invention described above provides for the art a variable flow resistance 25 system for use in an underground well. This system 25 may include a first flow channel 48, 112 and a first network of one or more branch ducts 94a-c, 100, 102a-s crossing the first flow channel 48, 112. In this way, a portion of the fluid mixture 36 discharged from the first flow channel 48, 112 to the first network of branch ducts 94a-c, 100, 102a-c, varies depending on at least one of the following characteristics: a) the viscosity of the fluid mixture 36 and b) the speed of the fluid mixture 36 in the first flow channel 48 , 98.

Optimally, a portion of the fluid mixture 36 discharged from the first flow passage 48, 112 to the first network of branch ducts 94a-c, 100, 102a-c is increased in response to an increase in the viscosity of the fluid mixture 36.

Optimally, the portion of the fluid mixture 36 discharged from the first flow channel 48, 112 to the first network of vent channels 94a-c, 100, 102a-c is increased in response to a decrease in the speed of the fluid mixture 36 in the first flow channel 48, 112.

The first network of branch channels 94a-c may direct the fluid mixture 36 to the first control channel 68 of the flow path switch 50. This flow path switch 50 may select which of the plurality of flow paths 54, 56 will go the predominant part of the fluid after the switch 50, and this the choice depends, at least in part, on the portion of the fluid mixture 36 discharged to the first control channel 68.

System 25 may include a second flow channel 44 with a second network of one or more branch ducts 98a-c that intersect the second flow channel 44. In this configuration, a portion of the fluid mixture 36 discharged from the second flow channel 44 to a second network of branch ducts 98a-c preferably increases with increasing viscosity of the fluid mixture 36 and increases with decreasing velocity of the fluid mixture 36 in the second flow channel 44.

The second flow channel 44 may direct the fluid mixture 36 to the second control channel 64 of the flow path switch 50. This flow path switch 50 can choose which of the plurality of flow paths 54, 56 will go the predominant part of the fluid from the switch 50, and this choice depends on the ratio of the flow rates of the fluid mixture 36 through the first and second control channels 64, 68. In an optimal embodiment, the ratio of the flow rates of the fluid mixture 36 through the first and second control channels 64, 68 varies depending on the ratio of neigh desired to undesired fluid in the composition of the mixture fluid 36.

The first network of branch ducts 94a-c, 100, 102a-s may include a plurality of branch ducts located at certain intervals between them along the first flow channel 48, 112. At each point of intersection of the branch ducts 94a-c, 100, 102a-s with the first a flow channel 48, 112 can be formed chamber 96a-s, 104a-s.

Each of the chambers 96a-c, 104a-c has a volume for the fluid, and these volumes can decrease in the direction of flow of the fluid mixture 36 through the first flow channel 48, 112. The passage section of the first flow channel 48, 112 can increase at each of the many intersections the first flow channel 48, 112 with a first network of branch channels 94a-s, 102a-s.

Also described above is a system 25 of variable resistance to flow of a fluid mixture 36 in an underground wellbore, comprising a flow path switch that selects from a plurality of flow paths 54, 56 the predominant portion of the fluid after the switch will go, depending on the ratio of the desired fluid to the undesired the composition of the fluid mixture 36.

The flow path switch 50 may include a first control hole 70. The flow rate of the fluid mixture 36 through the first control hole 70 affects which of the plurality of flow paths the majority of the fluid will go after the switch 50. The flow rate of the fluid mixture 36 through the first control hole 70 preferably varies depending on the ratio of the content of the desired fluid to the undesirable in the composition of the fluid mixture 36.

The flow path switch 50 may also comprise a second control hole 66. The flow path switch 50 may select which of the plurality of flow paths 54, 56 will flow the bulk of the fluid after the switch 50 depending on a) the flow rate of the fluid mixture 36 through the first control the hole 70 to b) the flow rate of the fluid mixture 36 through the second control hole 66. The ratio of the flow rates of the fluid mixture 36 through the first and second control holes 70, 66 preferably varies depending the ratio of the ratio of the content of the desired fluid to the undesirable in the composition of the fluid mixture 36.

The fluid mixture 36 can pass to the first control hole 70 through at least one control channel 68 in communication with the flow channel 48 through which the fluid mixture 36 passes. The flow rate of the fluid mixture 36 when passing from the flow channel 48 to the control channel 68 can vary depending on the ratio of the content of the desired fluid to the undesirable in the composition of the fluid mixture 36. The portion of the fluid mixture 36 that passes from the flow channel 48 to the control channel 68 may increase with increasing viscosity fluid mixture 36 and / or decrease with increasing speed of the fluid mixture 36 in the flow channel 48.

The flow path switch 50 may include a second control hole 66. The flow rate of the fluid mixture 36 through the second control hole 66 affects which of the plurality of flow paths the main body of fluid will go after the switch 50.

The fluid mixture 36 passes to the second control hole 66 through at least one control channel 64 through which the fluid mixture 36 passes. The control channel 64 is connected to at least one flow channel 44, and the flow rate of the fluid mixture 36 when passing from the flow channel 44 to the control channel 64 may vary depending on the ratio of the content of the desired fluid to the undesirable in the composition of the fluid mixture 36.

The portion of the fluid mixture 36 that extends from the flow channel 44 to the control channel 64 may decrease with increasing viscosity of the fluid mixture 36 and / or increase with increasing speed of the fluid mixture 36 in the flow channel 44.

The invention described above also provides a variable flow resistance system 25 for a fluid mixture 36 in an underground well, the system 25 including a flow chamber 84. The predominant part of the fluid mixture 36 enters the chamber in a direction that varies depending on the ratio of the desired fluid to the undesired composition fluid mixture 36.

The fluid mixture 36 can flow more directly through the chamber 84 to the outlet 40 of the chamber 84 in response to an increase in the ratio of the desired fluid to the undesired fluid 36.

The predominant part of the fluid mixture 36 enters the chamber 84 through one of the plurality of inlets 86, 88. That input from the plurality of inlets 86, 88 to which the main part of the fluid mixture 36 receives is selected depending on the ratio of the content of the desired fluid to the undesirable in the composition of the fluid mixtures 36.

The first inlet 88 directs the flow of the fluid mixture 36 in a more direct way to the outlet 40 of the chamber 84 than the second inlet 86. The first inlet 88 can direct the flow of the fluid mixture 36 more radially to the outlet 40 than the second inlet 86. The second inlet 86 can direct the fluid 36 to exit 40 along a more spiral path than first entrance 88.

The chamber 84 may have a generally cylindrical shape, and the fluid mixture 36 can spiral more strongly into a spiral inside the chamber 84, the greater the ratio of the content of the desired fluid to the undesirable in the composition of the fluid mixture 36.

System 25 preferably comprises a flow path switch 50 that selects which of the plurality of flow paths 54, 56 will go the predominant portion of the fluid after the switch, depending on the ratio of the desired fluid to the undesired fluid 36.

The flow path switch 50 may include a first control orifice 70. The flow rate of the fluid mixture 36 through the first control orifice 70 affects which of the plurality of flow paths 54, 56 will pass the predominant portion of the fluid after the switch. The flow rate of the fluid mixture 36 through the first control hole 70 in the preferred embodiment, varies depending on the ratio of the content of the desired fluid to the undesirable in the composition of the fluid mixture 36.

The flow path switch 50 may also include a second control hole 66. The ratio of a) the flow rate of the fluid mixture 36 through the first control hole 70 to b) the flow velocity of the fluid mixture 36 through the second control hole 66 affects which of the plurality of paths 54, 56 of the flow will go the predominant portion of the fluid after the switch. The ratio of the flow rates of the fluid mixture 36 through the first and second control openings 70, 66 preferably varies depending on the ratio of the content of the desired fluid to the undesirable in the composition of the fluid mixture 36.

The fluid mixture 36 can pass to the first control hole 70 through at least one control channel 68 in communication with the flow channel 48 through which the fluid mixture 36 passes. The flow rate of the fluid mixture 36 when passing from the flow channel 48 to the control channel 68 can vary depending on the ratio of the content of the desired fluid to the undesirable in the composition of the fluid mixture 36.

The flow path switch 50 may include a second control hole 66. The flow rate of the fluid mixture 36 through the second control hole 66 affects the way in which the predominant portion of the fluid flows from the plurality of flow paths 54, 56 after the switch 50. The fluid mixture 36 passes to the second control hole 66 through at least one control channel 64 through which fluid mixture 36 passes.

The control channel 64 is connected to at least one flow channel 44. The flow rate of the fluid mixture 36 as it passes from the flow channel 44 to the control channel 64 varies depending on the ratio of the desired fluid to the undesired fluid 36.

The above described system 25 variable resistance to flow of a fluid mixture 36 in an underground well containing a flow chamber 84. The predominant part of the fluid mixture 36 enters the chamber 84 in a direction that varies depending on the speed of the fluid mixture 36.

The fluid mixture 36 may pass through the chamber 84 to the exit 40 of the chamber 84 in a more direct way in response to a decrease in speed.

The predominant part of the fluid mixture 36 may enter the chamber 84 through one of the many inlets 86, 88. This one of the many inlets is selected depending on the speed. The first inlet 88 from the plurality can direct the fluid mixture along a more direct path to the exit 40 from the chamber 84 than the second inlet 86 from the plurality of inlets.

The first inlet 88 may direct the flow of the fluid mixture 36 more radially to the outlet 40 of the chamber 84 than the second inlet 86. The second inlet 86 may direct the fluid mixture 36 to the outlet 40 along a more spiral path than the first inlet 88.

The chamber 84 may have a generally cylindrical shape, and the fluid mixture 36 may spiral more strongly into a spiral inside the chamber 84, the higher the speed.

The system 25 preferably comprises a flow path switch 52 that selects which of the plurality of flow paths 58, 60 will go the predominant portion of the fluid after the switch 52, and this choice depends on the speed of the fluid mixture 36.

Also described above is a variable flow resistance system 25 for use in an underground well, the variable flow resistance system 25 comprising a flow chamber 84 having an outlet 40, at least first and second inlets 116, 110. The fluid mixture 36 entering the flow chamber 84 through the second inlet 110 counteracts the flow of the fluid mixture 36 entering the flow chamber 84 through the first inlet 116, thereby resisting the flow of the fluid mixture 36 through the flow chamber 84 in accordance with the ratio flows through the first and second inputs 116, 110.

The resistance to flow of the fluid mixture 36 through the flow chamber 84 may decrease as the flows through the first and second inlets 116, 110 become more equal to each other. The flows through the first and second inlets 116, 110 may become more equal to each other as the viscosity of the fluid mixture 36 increases, as the speed of the fluid mixture 36 decreases, as the density of the fluid mixture 36 decreases and / or as the ratio of the desired fluid to the undesired in the composition of the fluid mixture 36.

The resistance to flow of the fluid mixture 36 through the flow chamber 84 may increase as the flows through the first and second inlets 116, 110 become less equal.

The fluid mixture 36 can enter the first inlet 116 through the first flow channel 112, oriented generally tangentially with respect to the flow chamber 84. The fluid mixture 36 can enter the second inlet 110 through the second flow channel 112, oriented generally tangentially with respect to the flow chamber 84, and the second channel 114 may receive a fluid mixture 36 from the branch from the first flow channel 112.

It should be understood that the various options described above can, without violating the principles of the present invention, be applied in various positions, for example, in an inclined, inverted, horizontal, vertical, etc., as well as in various configurations. The embodiments of the invention presented in the drawings are shown and described simply as examples of the beneficial application of the principles of the present invention, while these principles are not limited to any specific details of these options.

It will be understood by a person skilled in the art from the above description of embodiments of the invention that many modifications can be made to these specific embodiments, many additions, substitutions, deletions, other changes can be made, and such changes will be within the scope of the present invention. Accordingly, the above description should be taken only as an illustration and example, and the scope and essence of the invention are limited solely by the paragraphs of the attached claims and their equivalents.

Claims (16)

1. The system of variable resistance to flow, designed for use in an underground well and containing a first flow channel and a first network of one or more outlet channels intersecting the first flow channel, while part of the fluid mixture discharged from the first flow channel to the first network of outlet channels, varies depending at least on the viscosity of the fluid mixture or on the speed of the fluid mixture in the first flow channel,
the first network of outlet channels is capable of directing the fluid mixture to the first control channel of the flow path switch, capable of selecting one of a plurality of flow paths, through which the predominant part of the fluid passes after the switch, at least partially depending on the part of the fluid flow to the first control channel. 2. The system according to claim 1, which further comprises a second flow channel and a second network of one or more outlet channels intersecting the second flow channel, while a portion of the fluid mixture discharged from the second flow channel to the second network of outlet channels increases with increasing viscosity fluid mixture and while reducing the speed of the fluid mixture in the second flow channel. 3. The system according to claim 2, in which the second flow channel is capable of directing the fluid mixture to the second control channel of the flow path switch, capable of selecting one of a plurality of flow paths through which the predominant part of the fluid passes after the switch, depending on the ratio of the flow rates of the fluid mixtures through the first and second control channels. 4. The system according to claim 3, in which the ratio of the flow rates of the fluid mixture through the first and second control channels varies depending on the ratio of the content of the desired fluid to the undesirable fluid in the fluid mixture. 5. The system according to claim 1, which further comprises a second flow channel directing the fluid mixture to the second control channel of the flow path switch, capable of selecting one of a plurality of flow paths through which the predominant part of the fluid passes after the switch, depending on the ratio of flow rates fluid mixture through the first and second control channels. 6. The system of variable resistance to flow, designed for use in an underground well and containing a first flow channel and a first network of one or more outlet channels intersecting the first flow channel, while part of the fluid mixture, diverted from the first flow channel to the first network of outlet channels, varies depending at least on the viscosity of the fluid mixture or on the speed of the fluid mixture in the first flow channel, while the first network of outlet channels contains many outlet channels, located at intervals between them along the first flow channel. 7. The system according to claim 6, which further comprises a camera at each of a plurality of intersection points of the first flow channel and the drain channels. 8. The system according to claim 7, in which each chamber has a volume for a fluid mixture, while these volumes are reduced in the direction of flow of the fluid mixture through the first flow channel. 9. The system according to claim 6, in which the orifice of the first flow channel increases at each of the multiple intersections between the first flow channel and the first network of branch channels. 10. A variable flow resistance system for use in an underground well and comprising a flow chamber, wherein the predominant portion of the fluid enters the chamber in a direction that varies depending on the ratio of the content of the desired fluid to the undesirable fluid in the fluid, and a path switch flow path, choosing a path from a plurality of flow paths along which the predominant part of the fluid passes after the switch, depending on the ratio of the content of the desired fluid food to undesirable fluid in a fluid mixture. 11. The system of claim 10, wherein the flow path switch comprises a first control orifice, wherein the flow rate of the fluid mixture through the first control orifice affects the selection of the path from the plurality of flow paths that most of the fluid passes after the switch. 12. The system according to claim 11, in which the flow rate of the fluid mixture through the first control hole varies depending on the ratio of the content of the desired fluid to the undesirable fluid in the fluid mixture. 13. The system of claim 11, wherein the flow path switch further comprises a second control hole, wherein the ratio of the flow rates of the fluid mixture through the first and second control holes affects the choice of the path from the multiple flow paths that the predominant part of the fluid will follow after the switch . 14. The system according to item 13, in which the ratio of flow rates through the first and second control holes varies depending on the ratio of the content of the desired fluid to the undesirable fluid in the fluid mixture. 15. The system according to claim 11, in which the fluid mixture passes to the first control hole through at least one control channel connected to the flow channel through which the fluid mixture passes, while the flow rate of the fluid mixture when passing from the flow channel into the control channel varies depending on the ratio of the content of the desired fluid to the undesirable fluid in the fluid mixture. 16. The system of claim 11, wherein the flow path switch comprises a second control hole, wherein the flow rate of the fluid mixture through the second control hole affects the choice of the path from the plurality of flow paths that the predominant part of the fluid passes after the switch, the fluid mixture passes to the second control hole through at least one control channel, which is connected to at least one flow channel, while the flow rate of the fluid mixture from the flow channel to the control channel al varies depending on the ratio of the content of the desired fluid to undesired fluid in the fluid mixture.

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